Marlins GM Larry Beinfest was on WQAM this morning with Hank Goldberg. Today's interview wasn't terribly insightful, but they did talk about Castillo's injury. All they know as of now is that it's a quadriceps issue - in his left leg, which is opposite the hip issue he's been struggling with (Craig mentioned all of that in the comments last night, I know).
Beinfest also said that last week Castillo was having issues with his right quadriceps. Not to put words in anyone's mouth here, but my guess is that the quad issues are a result of him compensating for the hip. I'll try to get some specifics from Will Carroll today.
Other than that, Beinfest and Goldberg mostly talked about the Heat. Larry was looking for tickets to tonight's game (jokingly, since the Fish play at about the same time as the Heat). Keep that in mind though as you make your guesses for tonight's attendance later. I'm guessing a number of folks are going to the Heat game tonight, or are going to stay home and watch some of both - instead of heading out to JRS.
Update [2005-5-10 by mike42]: I forgot to mention earlier that Beinfest said that Castillo will not be in the lineup tonight. Please adjust your ichthyomancy accordingly.